We investigated the characteristics of various Tofu coagulants extracted from sea tangle using treated deep ocean water (DOW) as the solvents. The coagulants were typical solutions extracted from sea tangle using raw DOW and strongly electrolyzed acidic (SAC) or alkaline (SAK) water. The total dissolved solids (TDS), NaCl and electric conductivity were increased in the coagulant solution extracted by SAC than the others. In the coagulant solutions extracted by acidic electrolyzed solvent, aspartic acid content (13.5 mg/100 g) was higher than others (11.2 and 12.1 mg/100 g). The Tofu obtained using coagulants extracted with treated DOW had the water contents ranging from 79.55% to 80.04%. The contents of crude protein (12.1 g/100 g) and Na, Ca, K and Mg were relatively higher than general Tofu commercially available. Therefore, coagulant solutions extracted from sea tangle using treated DOW can be used to develop natural high-grade tofu for practical use.

To optimize the mixing ratio of ingredients to obtain the best sensory qualities, a response surface methodology with a central composite design was performed on hot water extracts using crucian carp Carassius carassius treated with diluted vinegar (pH 5.24-5.30). The optimal solutions for four parameters (overall acceptability, odor, flavor, and taste) were obtained using the second-order response surface regression models. The optimal formulation appeared to be 124.15 g of ginger and 96.09 g of garlic with 1 kg of ground crucian carp meat based on the desirability function technique.

Photosensitized extracts of 28 seaweed species were tested in vitro to examine the variation in their algicidal activities against the toxic microalga Cochlodinium polykrikoides. When both seaweed extracts and microalgae were exposed to UV and visible light, methanol extracts of Porphyra yezoensis showed 5.7- and 4.4-fold increasesin light-dependent algicidal activity, respectively. When only seaweed extracts were exposed to both UV (365 nm) and visible light (white lamp) at the same time, methanol extracts of Enteromorpha linza and Carpopeltis affinis showed 3.3- and 3.4-fold increases in algicidal activity, respectively. When UV-photosensitized extracts were left in the dark, the algicidal activity of Ecklonia cava increased 13-fold after 5 h. When visible light-photosensitized extracts were left in the dark, the algicidal activity of Monostroma nitidum increased by 3.3-fold in 1 h.

We identified a microsatellite marker, Poli121TUF, which appears to be significantly linked (P<0.001) with a lymphocystis disease virus (LCDV)-resistance gene in the olive flounder, Paralichthys olivaceus. The olive flounder is an economically important food fish, that is widely cultured in Korea, Japan, and China. Lymphocystis disease has spread in these countries and has seriously reduced the economic value of the fish. LCDV causes lymphocystis cells (LC) to form on the body surface, fins, gills, mouth, and intestine. Fish with LC lose commercial value due to their deformed appearance. The identified micro satellite marker can be used as a candidate locus for marker-assisted selection (MAS) in order to enhance the efficiency of selection for LCDV resistance in the olive flounder.

In 2006, we studied herbivore consumption rate and preference for algal species using laboratory experiments. In the no-choice feeding experiment, three herbivores (two sea urchins, Stronglyocentrotus nudus and Stronglyocentrotus intermedius and an abalone, Haliotis discus hannai) showed significantly (P<0.05) distinct preferences for four algae (Laminaria japonica, Undaria pinnatifida, Costaria costata and Ecklonia stolonifera). The alga preferred by S. nudus was L. japonica followed by U. pinnatifida, C. costata and E. stolonifera with respective daily feeding rates of . A similar trend was found for S. intermedius. Interestingly, the herbivore consumption rates for the algae differed with or without competition. The competition stimulated the feeding activity for S. nudus, but lowered the activity for S. intermedius. The multi-choice feeding experiment confirmed that L. japonica was significantly preferred by two herbivores: S. nudus and H. discus hannai (Duncan`s multiple range test, ANOVA, p<0.05).

We investigated the reproductive cycle of the striped eel catfish Plotosus lineatus. Specimens were sampled in the coastal waters of Sungsan and Jocheon, east of Jeju, Korea, from September 2001 to August 2002. The gonadosomatic index (GSI) in females and males were reached a maximum in June and July , respectively. Based on histological observations and GSI variation, the reproductive cycle was classified into the following successive stages: in females, growing (September-April), mature (April-June), spawning (June-July), and degenerative and recovery (July-September) and in males, growing (August-December), mature (September-May), spent (April-July), and degenerative and recovery (June-August). The total length at 100% maturity exceeded 15 cm and the fecundity ranged from 525 to 1176 eggs. The fecundity was correlated positively with total length and body weight. Histological observations of the gonads suggest that this species is a spring-summer spawner with group-synchronous type oocyte development.

Spermiogenesis and mature spermatozoa of the Korean false minnow Pseudogobio esocinus (Cyprinidae) are described by means of scanning and transmission electron microscopy. Spermiogenesis is characterized by lateral development of the flagellum, absence of nuclear rotation, and eccentric nuclear fossa formation. The spermatozoa have a spherical head containing a nucleus with highly condensed chromatin and no acrosome. The nuclear fossa contains the proximal centriole and anterior part of the distal centriole. The midpiece is type A II and contains semi-fused mitochondria around the axoneme. However, the symmetrical distribution of 4 or more the mitochondria does not follow a general pattern of the cyprinid spermatozoa. Cytoplasmic vesicles in the midpiece are common in Cypriniformes and some of Siluriformes and Characiformes spermatozoa.

We studied oocyte steroidogenesis in relation to oocyte development in the greenling, Hexagrammos otakii, a marine multiple spawner. Vitellogenic and mature oocytes were incubated in vitro in the presence or absence of as a precursor. The major metabolites were androgens [androstenedione and testosterone (T)] and estrogens [ and estrone ()] in vitellogenic oocytes. The metabolic rate of T was lower in 1.08 to 12-mm oocytes, while that of increased with oocyte size. The endogenous productions of T, and 17 , 20 were quantified using a radioimmunoassay in the non-precursor group. The endogenous levels of T and were highest in 1.08 to 12-mm oocytes and was produced only in 1.90 to 95-mm oocytes. The relationship between oocyte size and steroidogenesis showed that 1.08 to 12-mm oocytes are full vitellogenic following induction of the maturation process. Moreover, acts as a maturation inducing hormone in H. otakii.

The coarse deposit with a lower mud content adjacent to the shelf of the southern East Sea is probably a "relict" sediment deposited in response to a lower stand of sea level during the Pleistocene. The sediment that developed on the slope and in the deep sea was river-borne primarily and was secondarily reworked or redistributed by the Tsushima Warm Current from the East China Sea. The clay mineralogy of the area suggests various sources of fine-grained sediment from adjacent rivers, the Korea Strait, volcanic material from Ulleung Island, and the Japan coast. Massive sand, bioturbated mud, homogeneous mud, and laminated mud were the dominant facies found in the core sediments from the study area. The massive sand was mainly volcanic ash from an eruption on Ulleung Island (9300 yr BP) and consisted of colorless pumiceous glass and a black scoriaceous type. The sedimentation rates on the slope, based on the Ulleung-Oki ash layer, were about 10cm/ky higher than in the basin. Other than the coarse-grain sediment, the mean size of the fine sediment dominating the bioturbated and homogeneous muds in the basin and the laminated mud on the slope was 6-10 phi. This indicates a difference in the major sedimentary process: hemipelagic sedimentation in the Ulleung Basin and mass flow deposition, such as turbidite, on the slope of the southern East Sea.

We measured the salinity, pH, and concentrations of and nutrients in groundwater in the southeastern coastal aquifer off Busan from March to September 2005 to evaluate its submarine discharge and geochemical characteristics. Salinity in coastal groundwater increased sharply at 20 m depth and exceeded 25 ppt below 40 m during the study period, indicating that a strong transition zone between fresh groundwater and seawater developed between 20 and 40 m depths. Fresh groundwater in the upper layer of this transition zone was characterized by high pH, , dissolved inorganic nitrogen (DIN), and dissolved inorganic phosphorus (DIP) and low dissolved inorganic silicate (DSi) relative to seawater in the lower layer. In addition, the vertical profiles of the , DIN, and DIP concentrations imply that a strong advective groundwater flow occurs along the interface of fresh groundwater and seawater near 20 m depth. The geochemical constituents in coastal groundwater also showed strong seasonal variation, with the highest concentrations in summer (June 2005) due to the changes of groundwater recharge and sea level. This implies that the input of terrestrial chemical species into the coastal ocean through submarine groundwater discharge (SGD) could change seasonally. To ascertain the seasonal variation of SGD and SGD-driven chemical species fluxes, and associated ecological responses in the coastal ocean, more extensive studies are necessary using various SGD tracers or seepage meters in the future.